The use of computer chips which can be operated contactlessly and in which wired leads are dispensable (“ubiquitious computing”) is increasingly gaining in importance. An important area of application for this technical field is sensor technology, since a wire-free communication of a sensor signal to a central control unit is desirable for many applications of sensors.
The communication of such a contactless sensor computer chip with a central control or computing unit for the further processing of a contactlessly communicated sensor signal may be effected for example via a wire-free network (e.g., Bluetooth™).
Since a cost-effective, mechanically independent and universally deployable usability is desirable in the case of such wire-free computer chips, a wire-free energy supply is sought for such computer chips. The need for a wire-based power supply would lead to very high costs and additionally restrict the possibilities of use.
In the case of contactless identification labels (so-called “ID tags”), an electromagnetic field is coupled into the identification label often using a coil contained in the identification label. Using a rectifier, the electrical energy coupled in inductively can be rectified, so that it is possible to provide a DC current for supplying the identification label. However, this type of energy supply has the disadvantage that the identification label, for inductively coupling in electromagnetic field energy, always has to be positioned in a region with a very high electric field strength, which greatly limits the range of such a contactless chip.
Li, W. J. et al., “A micromachined Vibration-Induced Power Generator for Low Power Sensors of Robotic Systems”, in: Jamshidi, M. et al. (eds.) “Robotic and Manufacturing Systems, Recent Results in Research, Development and Applications”, Vol. 10, p. 482–488, TSI Press Series, Albuquerque, USA, discloses a macroscopic generator with a total volume of approximately one cubic centimeter, in which a permanent magnet, for example a rare earth permanent magnet having a weight of 21 milligrams, is arranged in the central region of a copper spring, and is exposed to vibration. An induced voltage can be induced in a coil on account of the temporally variable magnetic field generated by the vibrating permanent magnet, said induced voltage being used for example for supplying an electrical load that is provided externally.
However, the generator described in Li, W. J. et al., which is to be connected to an electrical load and serves for generating energy from the vibration of a macroscopic permanent magnet is complicated to produce and still has a volume that is too large for some applications.
U.S. Pat. No. 6,475,639 B2 describes sensors and actuators and also microelectromechanical systems (MEMS).
Ching, N. N. H. et al., “A laser-micromachined multi-modal resonating power transducer for wireless sensing systems”, in: Sensors and Actuators A, vol. 97–98, April 2002, p. 685–690, describes a generator for generating energy from vibration with a total volume of ˜1 cm3, which generator uses laser-produced springs in order to convert mechanical energy into electrical energy by means of Faraday's law.
U.S. Pat. No. 4,857,893 discloses a transponder unit which receives a carrier signal from an interrogation device.
Ahn, C. H. et al., “A Fully Integrated Micromagnetic Actuator with a Multilevel Meander Magnetic Core”, in: Technical Digest, IEEE Solid-State Sensor and Actuator Workshop, Hilton Head Island S.C., June 1992, describes a fully integrated micromagnetic actuator with a multilevel meander magnetic core.
Williams, C. B. et al., “Development of an Electromagnetic Micro-Generator”, in: Proceedings-Circuits, Devices and Systems, vol. 148, No. 6, December 2001, p. 337–342, describes a design methodology for linear microgenerators and is applied to the design of an mm scale electromagnetic microgenerator.
El-hami, M. et al., “Design and Fabrication of a New Vibration-Based Electromagnetic Power Generator”, in: Sensors and Actuators A, vol. 92, No. 1–3, August 2001, p. 335–342, describes a device for generating electrical energy from mechanical energy in a vibrating environment.